"Oh... it's the Kaio-ken attack. It's like a massive upsurge of energy. Everything is heightened: power, speed, even hearing and vision improve dramatically. You sort of become a super-self. But it can only be sustained for a short time, so you have to get the job done quickly."
— Goku in "Lesson Number One"

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Similar Techniques

Kaio-ken (界かい王おう拳けん,Kaiōken, lit. "Fist of the King of the Worlds" or "Worlds' King's Fist") is a fighting technique invented by King Kai; however, Goku is the only person ever able to use it successfully. It is a technique that multiplies the user's ki for a "heart beat" - thus increasing their power and speed and enabling them to inflict serious damage to opponents who are considerably stronger than them. However, the downside of the Kaio-ken is that it takes a heavy toll on the user's body, making them more vulnerable to enemy attacks. While in the state, the user's aura color becomes crimson. The technique requires the use of ki control to handle it properly.

Contents

Overview

Goku uses the Kaio-ken on Planet Namek

As a result of the Kaio-ken, the user's base power level, strength, speed, and senses greatly increase for an instant (though training can allow for longer use shown during Goku's fight with Frieza). The only change produced by the basic Kaio-ken to be quantified in the series is that it doubles the user's power level.[6] As the series progresses, Goku demonstrates the ability to heighten the effect of the Kaio-ken to increasingly higher multiplications. There is an inconsistency in that Kaio-ken and Kaio-ken x2 appear to have the same effect, despite Goku and King Kai apparently believing the latter to be a more powerful buffer. Despite this, Kaio-ken x3 and above all consistently multiply the user's power level by the respective multipliers.[7]

Goku hits Vegeta with the Kaio-ken

In Dragon Ball Z, when Goku first learned the Kaio-ken, the furthest he could handle was the Kaio-ken x4 (though his body was heavily damaged). However, through training at 100x gravity and then later with his dramatic strength increase after his fight with Captain Ginyu, he was able to withstand astounding multiplications of the Kaio-ken technique, such as Kaio-ken x10 and Kaio-ken x20 (which is said to be the maximum in the anime). The highest multiplication for the Kaio-ken ever seen was the Kaio-ken x100, which Goku used against Lord Slug.[8] The technique, however, has its substantial flaws. If the user multiplies their base ki too much, the uprise of ki flowing inside could easily obliterate them, or severely damage their body, as it did Goku's. After using the Kaio-ken x4 to overpower Vegeta's Galick Gun, Goku's entire body was thrashed, and he could barely move without hurting himself. Even one friendly slap on the back from a gracious Yajirobe caused Goku to scream out in agony. King Kai tried to master this technique himself, but failed and taught Goku instead.

In Dragon Ball Super, it was mentioned by Old Kai that using Kaio-ken alongside Super Saiyan is almost impossible or rather lethal, because the intense emotional turmoil caused by the Super Saiyan transformation would not allow precise ki control to survive the technique.

Usage and Power

Dragon Ball Z

Goku disables Nappa with the Kaio-ken

The first time Goku used the Kaio-ken was during the Saiyan conflict when he used it to catch up with and crippleNappa before he could kill Gohan and Krillin with his Break Cannon mouth blast. Later, while Goku started to battle Vegeta, he realized he could not defeat Vegeta even with the Kaio-ken; so he powered up to Kaio-ken x3, raising his battle strength to over 24,000 and overpowering Vegeta. To prevent Vegeta from destroying the Earth with his Galick Gun, he used a Kaio-ken x3 Kamehameha, a combination of the Kaio-ken x3 and the Kamehameha, in an attempt to save himself and the Earth, initiating a Beam Struggle. When both of their attacks proved unable to overtake the other, Goku used the Kaio-ken x4, surging through Vegeta's Galick Gun and blasting him into the sky.

Goku uses the Kaio-ken x3 against Vegeta

Goku also used the Kaio-ken briefly when he fought Vegeta's Great Ape form, but was whipped aside by Vegeta's tail, surprised at Vegeta for remaining as agile as ever even in the huge size of the Great Ape transformation. During the Battle on Planet Namek, Goku uses the ability during his fight with Jeice and Burter in order to increase his power up to 300,000 according to Dragon Ball Z: The Anime Adventure Game, so that he could outmatch Burter and Jeice's combined power level of 175,000. Later when Goku fought Captain Ginyu, he demonstrated his Kaio-ken in a prolonged way, increasing his battle strength to a power level around 180,000, thus shocking Ginyu and Jeice. After being healed in the rejuvenation chamber following his attack from Vegeta when Goku himself had switched bodies with Ginyu, Goku battled with Frieza using a Kaio-ken once again.

Goku hits Frieza with the Kaio-ken x20

After realizing Goku was stronger than the others he had battled from Ginyu to Piccolo and even Vegeta, Frieza used 50% of his maximum power, which gave him an enormous power boost. According to Tien Shinhan and King Kai in the manga (as well as the English dub of Dragon Ball Z Kai), Goku was using Kaio-ken x10 throughout the fight, to have even a chance at battling Frieza, but even this was not nearly enough. Goku then attempted to use the Kaio-ken x20, which very briefly gave him speed and power enough to strike Frieza, setting him up for a Kamehameha, which Frieza amazingly held off with one hand before taking the full extent of the blast. Unfortunately, though showing physical signs of being harmed, Frieza was barely hurt by the attack. He did, however, appear shocked by Goku's power, remarking that there was "something strange" about him and wondering how a Saiyan could have such "incredible power". The attack left Frieza feeling somewhat threatened, as he remarks to himself that he "must take him out now!" A short time later, Goku transformed into a Super Saiyan for the first time, which greatly overshadowed the Kaio-ken and gave him the strength to finally overpower Frieza.

The "Super Kaio-ken" combination Goku uses against Pikkon

Goku's battle against Frieza is the last time the Kaio-ken was used in the original manga, as the introduction of Super Saiyan outclassed it. However, in the anime filler fight against Pikkon at the Other World Tournament, Goku uses a Kaio-ken and Super Saiyan combination (something he calls a "Super Kaio-ken"), which gives him an incredible power increase. Because of this one instance, it appears that Goku can also demonstrate the Kaio-ken's usability in transformed states, which potentially means he can make his transformed forms many times stronger. However, Goku also is very exhausted after using it due to the stress of the Super Saiyan form combined with this technique and cannot perform this technique unless dead. If used alive, he would otherwise be killed using the Super Kaio-ken, so the Kaio-Ken was rendered obsolete for a long time. However, after Goku obtained the Super Saiyan Blue form and its perfect ki control during Dragon Ball Super, this sparked the return of the Kaio-Ken technique; which this time is combined with this powerful and easily controlled Super Saiyan form (see below).

Dragon Ball Super

Super Saiyan Blue Goku using the Kaio-ken x10

According to Goku, using Kaio-ken alongside the Super Saiyan forms would be too overwhelming on the body, due to the forms using a lot of stamina, and would most likely result in immediate death. However, when Goku obtained the Super Saiyan Blue form, which required perfect innate ki control and a calm mind, utilizing the Kaio-ken technique alongside it became possible. So during his training, Goku began developing a god-like kaio-ken technique for eventual use against Beerus. He first attempted the technique against Hit during the Tournament of Destroyers, noting that it was incomplete with only a 10% chance of success, meaning Goku needed absolute concentration when activating it, otherwise it would kill him. Goku succeeded in combining the transformation with the Kaio-ken x10, which gave him the ability to effectively counter Hit's improved Time-Skip technique. However, due to the Kaio-ken's risks, Goku could not keep fighting for very long, and ended up surrendering the match as his time had run out. After ending the technique, Goku was in extreme pain as he was suffering from extreme muscle contractions. Due to the reckless use of his Ki this way, Goku ended up suffering from Delayed Onset Ki Disorder for some time.

During the Project Zero Mortals, Goku used the Kaio-ken once again in Super Saiyan Blue form while fighting Fused Zamasu. He did this as a last resort to break Fused Zamasu's Barrier of Light after losing strength in both of his arms and having his left leg crushed. Though he succeeded in knocking Fused Zamasu down with a swift kick from his right leg thanks to the Kaio-ken, Goku was immediately drained of his power afterwards and required a Senzu Bean.

Goku used the Super Saiyan Blue Kaio-ken yet again during his fight with Bergamo at the Zen Exhibition Match, after realizing his power to grow stronger and bigger through his punches. He later used it again during his fight with Toppo.

While sparring with Gohan, his son asked Goku to fight with all of his strength. Goku complied, and Goku fought briefly with Gohan. While Gohan was able to keep up with Goku when he was a Super Saiyan Blue, he was quickly defeated when Goku used Kaio-ken.

Film Appearances

Goku performing the Kaio-ken in Dragon Ball Z: The World's Strongest

In Dragon Ball Z: The World's Strongest, he first uses it to deflate the bio-warrior Misokatsun. He uses it again soon after to free himself after being frozen solid by Ebifurya, and then easily takes out both Ebifurya and Kishime with it. He later uses the Kaio-ken x3 to attack Dr. Wheelo's giant robotic body and succeeds in breaking off Wheelo's right arm. The two then engage in a Beam Struggle similar to the one Goku and Vegeta have in the Saiyan Saga, and, just like in that struggle, Goku overpowers Wheelo's blast by using the Kaio-ken x4.

In Dragon Ball Z: The Tree of Might, Goku first uses the Kaio-ken to avoid getting hit by the Great Ape Gohan, but is eventually knocked down by him. Goku later uses the Kaio-ken again to defeat all of Turles' henchmen. After Turles becomes more powerful with the fruit from the Tree of Might, Goku uses the Kaio-ken x10 (Kaio-ken x20 in the Funimation dub) to attack him, but is still unable to keep up.

In Dragon Ball Z: Cooler's Revenge, after Cooler transforms and becomes far more powerful, Goku uses the Kaio-ken to attack him, but has no success. Cooler even flies through Goku's Kaio-ken Kamehameha combo.

In Dragon Ball Z: Supersonic Warriors, in Krillin's "What-If" story, after dying of the heart virus, Goku (with Fortuneteller Baba's help) returns to teach the Kaio-Ken and Spirit Bomb techniques to Krillin so he can protect the Earth in Goku's place. Krillin can use these techniques in his level 3 form. Both Goku and Krillin will have their Kaio-ken activated if they are in a team-battle as the last team member standing, and when activated it will drain their HP slowly.

In Dragon Ball Xenoverse, Kaio-ken appears as a transformation Super Skill usable by Goku (in his 1st and 4th Skillsets), Krillin (in his 5th Skillset), and Yamcha (in his 2nd Skillset). Goku can also use the X3 Kaio-ken (in his 5th Skillset) and X20 Kaio-ken (in his 6th Skillset)

"The higher your Ki when you transform, the greater the power-up! But it'll also become a great burden, so watch out!"— Xenoverse 2Kaio-ken Skill description

Future Warrior using Kaio-ken in Xenoverse 2

In Dragon Ball Xenoverse 2, all Kaio-ken skills have been united into a single Awoken Skill, giving higher levels of Kaio-ken based on how may filled ki bars the user has (1 to 2 bars for the standard Kaio-ken, 3 to 4 bars for 4x Kai-ken, and 5 or more for 20x Kai-ken). While in the Kaioken state, the user can revert to their base form by pressing the skill's assigned buttons to deactivate it. When in use the Kaio-ken drains stamina and will put the user into a guard break state if they run out of stamina while using it. Like in Xenoverse, it can be used by the Future Warrior regardless of race.

X10 Super Saiyan Blue Kaioken Goku model from Xenoverse 2

Unlike the previous game, Krillin and Yamcha can't use Kaio-ken, only Goku and the Future Warrior (Xenoverse 2) can use it, however unused voice data files indicate that it was planned to be used by Super Saiyan 4 Gogeta, Goten, and Goku Black in his playable base form as there are unused voice samples for it hidden within the game's voice date files. It can be obtained by the Future Warrior as a reward in Parallel Quest 08: "Invade Earth".

Additionally the Future Warrior and Goku can use the Kaioken Assault and Kaio-ken Kamehameha as separate Super Skills, along with the 4x and x20 version of Kaio-ken Kamehameha as separate Ultimate Skills. These skills can be use in conjunction with the Awoken Skill or without. They can even be used while in various Super Saiyan forms by the Future Warrior. After the Version 1.05.00 Update, SSGSS Goku can use the Super Saiyan Blue Kaio-ken as his Awoken Skill transformation in his Whis Symbol Gi 2 Skillset. While using his Super Saiyan Blue Kaio-ken state, Goku gains access to his X10 Super Saiyan Blue Kaio-ken form. Unlike the standard Kaioken, the Super Saiyan Blue Kaioken and X10 variant drain the user's Health instead of Stamina, and the health drain increases with the X10 multiplier. Due to the health drain, it makes both transformations more risky than the standard Kaioken and its multipliers (x3 and x20). Additionally due to game mechanics, the Kaio-ken based Super Skills can be utilized in conjunction with any of the Future Warrior's Awoken Skills that allows them to access their custom skillset (Purification, Become Giant, and Power Pole Pro are the exceptions). As a result the Saiyan Future Warrior can utilize it alongside any of their Super Saiyan forms including Super Saiyan (as well as its variants Super Vegeta and Future Super Saiyan) and Super Saiyan God Super Saiyan though the effect is only visual and there is no benefit for doing so other than the stat boost gained by the Awoken Skill transform though the benefits depend on the skill and transformation being used (as Super Saiyan boosts the effect of Strike Supers like Kaioken Assault while Super Vegeta boosts the effect of Ki Blast Super like Kaioken Kamehameha). Frieza Race Future Warrior can utilize them while in Turn Golden form and any race can utilize them together with Potential Unleased and Kaio-ken Awoken Skills, though again the only benefit is that granted by the transformation's stat boost and how it effects the skill in question which generally applies to most skills. As there is only a single Awoken Skill slot the Kaioken Awoken Skill cannot be utilized with any other Awoken Skill (while Goku's Super Saiyan Blue Kaioken and its X10 multiplier are classified as a separate Awoken Skill). After the 1.09.00 Update in Xenoverse 2, Goku can be customized via Partner Customization allowing him to have his Super Saiyan Awoken Skills (Super Saiyan, Super Saiyan 2, and Super Saiyan 3 as an all-in-one Awoken Skill or Super Saiyan by itself) and Kaio-ken based Super Skills in one Skillset, thus he is able to utilize these techniques together with his Super Saiyan forms due to game mechanics. Interestingly, despite being able to utilize it in Xenoverse, Krillin and Yamcha cannot be customized with it through their custom skillsets in Xenoverse 2 despite the fact that Nappa can acquire the Super Saiyan Awoken Skill (though only the initial transformation by itself) after unlocking it through Partner Customization.

In Jump Super Stars and its sequel Jump Ultimate Stars, the Kaio-ken is used as Goku's Special B/Up Special via his 5 Battle Koma version, where it only is used for that one brief attack, which varies between the games. In the first game, Goku is by default in his Super Saiyan form, making it identical to his Super Kaio-ken attack, and it works as a charge attack in order to reach the full sequence of blows when fully charged. In the sequel, Goku instead is still in normal form in BK5, while his Kaio-ken sequence now involves rapid button taps in order to get the full sequence.

In Dragon Ball Fusions, Goku uses a variation on the Kaiō-ken, called Maximum Kaio-ken (最大界王拳,Saidai Kaiō-ken, lit. Maximum World King Fist) in his Goku (Super), Super Saiyan Blue, and GT Goku playable forms. While Super Saiyan 4 Goku appears to be using it in trailers for Dragon Ball Fusions, he is actually using Maximum Charge and it should be noted that Maximum Kaio-ken does not appear as part of SSJ4 Goku's learnable Special Moveset (GT Goku and Super Saiyan 4 Goku appear as separate playable characters in Dragon Ball Fusions). Maximum Kaio-ken can also be used by several other playable characters as well such as the Namekian Uzma after reaching Lv. 99.

The standard Kaioken also appears as a Special Move that can be learned by certain characters. It can be learned by the Namekian Uzma after reaching Lv. 51.

Dragon Ball Online

A human character using the Kaio-ken

In the computer game Dragon Ball Online, which is set in Age 1000, it is said that between the end of the original manga and the start of the game, King Kai taught the Kaio-ken skill to the inhabitants of Earth. This includes Earthlings who since the end of the manga have began practicing different forms of martial arts, and the Namekians who fled to Earth after their planet was destroyed by Mira. The Majin race, who were not taught the technique, managed to learn it through mimicry. As such, the technique is obtainable by all three of the game's playable races.

Kaio-ken as it appears in Dragon Ball Online

The skill is learned by every class at level 35. The appearance and effects in the game are similar to how it appears in the anime: activating it engulfs the player in a flaring red aura. The self buff increases the players' movement speed, allowing them to run faster while traveling the environment, as well as their attack speed, chance of critical strike, and maximum attack power while in combat. During its use, both the player's LP (life) and EP (power) are drained and the skill cannot be deactivated manually, but instead deactivates itself when HP is considerably low. Kaio-ken also has a six-minute cooldown period.

The Kaio-ken technique can be amplified over x20, as never seen in previous uses by Goku in the original series. The only increase that comes with multiplying the Kaio-ken buff is the chance of critical strike; for example, activating it doubles the player's critical strike, and the following multiplication would put the increase at x3. Owing to it being accessible to all races and classes, it can be used to increase the strength of trademark techniques other than the Kamehameha, such as Special Beam Cannon, Wolf Fang Fist, Destructo Disc, and Big Bang Attack.

The only time Goku shouts "Kaio-ken times two" was briefly during the battle with Vegeta, in order to dodge an incoming energy blast. As previously mentioned, there appears to be no actual difference between the Kaio-ken and 2x Kaio-ken. According to the Daizenshuu, Goku's base power level at the time was 8,000 and Vegeta's was 18,000; Goku then powered up to 16,000 with the 2x Kaio-ken, and then 24,000 with the 3x Kaio-ken. If there was a difference between the Kaio-ken and 2x Kaio-ken, then Goku should not have needed to use the 3x Kaio-ken in order to overpower Vegeta.

In an episode of the original Saban dub, Goku shouts "Kaio-ken times ten" and then "Kaio-ken times twenty" as he fires two Kamehameha blasts toward a comet that his spaceship almost collides with.

The website for Dragon Ball Z: Battle of Gods states that "King Kai teaches Goku the "Kaio-ken" and how to gather energy from the planet into one great fighting energy ball. Later King Kai takes on the training of Yamcha, Tien, Chiaotzu, and Piccolo using the same techniques that were successful with Goku." It is unknown whether this statement refers to teaching the Z Fighters the Kaio-ken and Spirit Bomb techniques, or if it is referring to King Kai's training techniques.

However Yamcha does use the technique in Xenoverse as does Krillin (who trained under King Kai briefly after his death during the Fusion Saga in the anime before he was resurrected by Porunga). Krillin also learns the technique from Goku in his what-if saga in Supersonic Warriors. It should be noted that Krillin being able to use the technique is likely attributed to his skill when it comes to ki control. However neither Tien, Chiaotzu, or Piccolo have ever been show using the technique in any media.

Technically, Cell could use the Kaio-ken as well, due to having Goku's cells. However, this is not confirmed or shown in the anime or manga (though Cell does claim this in the Funimation dub of Dragon Ball Z Kai).

In Dragon Ball Xenoverse 2, if Male Voice Option 8 (again Chris Arnott/Takahata101 from Dragon Ball Z: Abridged) is selected for the Future Warrior, then they will shout "KAY-o-ken" when performing the Kaioken Assault Super Skill, though its mispronunciation is done on purpose as an in-joke reference to the common mispronunciation of Kaio-ken in various dubs.

Unused voice lines in Xenoverse 2 indicate that Gogeta can use the Kaio-ken as a Super Saiyan 4,[11] and Goten can also use the Kaio-ken (regular, Kaio-ken x3 and Kaio-ken x20).[12]

Additionally there are also unused voice lines for Goku Black indicating that he can use the Kaio-ken in his base form. This is ironic given the fact that Black is the former North Kai of Universe 10 and the Kaio-ken is a technique invented by the North Kai of Universe 7 who himself is unable to use it despite being its inventor. This would also make Black the only known Kai (former or current) capable of using a technique which ironically fits with its name's literal translation Fist of the King of the Worlds.[11][4] Black can utilize the Spirit Bomb in Super Dragon Ball Heroes another technique invented by the North Kai of Universe 7 that he is unable to use himself making Black the only Kai capable of using both of King Kai's signature techniques.

Gallery

Goku uses his Kaio-ken x20 against Frieza in the manga

Goku uses the Kaio-ken against Nappa

Goku uses the Kaio-ken x3

Goku unleashes a furious attack at Vegeta

Goku uses the Kaio-ken in his spaceship

Goku charges ki in his hands while using the Kaio-ken

Goku shows the Kaio-ken to Ginyu

Kaio-ken Goku on Namek

Goku uses the Kaio-ken against Ginyu

Goku uses the Kaio-ken x20 against Frieza

Goku using Kaio-ken x20 to attack Frieza

Goku uses the Kaio-ken in The World's Strongest

Goku using the Kaio-ken in The World's Strongest

Goku using the Kaio-ken x3 in The World's Strongest

Goku using the Kaio-ken x10 in The Tree of Might

Goku uses the Kaio-ken x10 against Turles

As Goku uses the Kaio-ken x100, giant projections of himself and Piccolo appear above him